1. Field of the Invention
This invention relates to ballast assemblies and more specifically to a novel and improved ballast assembly including a bobbin specially suited to automated construction methods.
2. Description of the Prior Art
A fluorescent lamp customarily requires a ballast for providing the necessry starting voltage. A ballast typically includes at least one transformer coil wound on a coil bobbin and certain associated circuitry which is known. The bobbin may be provided with metallic pins for interconnecting magnet wire ends coming from the coil to a printed circuit board assembly. Thus, the complete ballast assembly may include a printed circuit board assembly, as well.
Different lamps having different power requirements and starting voltages require different ballasts. One ballast may vary from another in the particular circuit components used, the size and shape of the transformer coil, or the locations of starts, taps and finishes on similarly sized transformer coils.
Until this invention, such ballasts were manufactured and assembled using methods which are highly manual labor intensive, with resulting labor costs per unit accounting for nearly half the total production cost per unit. Bobbin and transformer coil arrangements designed for and requiring further assembly to printed circuit assemblies are shown in A. G. Weyrich, U.S. Pat. No. 3,076,165, where terminal lugs are provided to be plugged into corresponding slots in a printed circuit board; and in D. A. Peterson, U.S. Pat. No. 4,347,490, where pins are similarly provided for electrical interconnections to associated electronic circuitry on a printed circuit board. Since a ballast may included the printed circuit board as well, a standardized method of assembling not only the coil and bobbin, but also the interconnection pins, printed circuit board and associated electronic circuitry, would substantially reduce the overall cost of producing ballasts.